RV Solar Calculator - Page 2 - Fiberglass RV
Journey with Confidence RV GPS App RV Trip Planner RV LIFE Campground Reviews RV Maintenance Take a Speed Test Free 7 Day Trial ×


Reply
 
Thread Tools Search this Thread Display Modes
 
Old 01-19-2020, 01:50 AM   #21
Senior Member
 
Name: Jon
Trailer: Bigfoot
California
Posts: 193
Quote:
Originally Posted by Rzrbrn View Post
JonV, my interpretation of the graph is that on Jan 4 you used about 93ah, but most days you used about 75ah. Is this correct?

JonR, Big Foot RV said that the furnace uses about 8 amps when in use, exactly what you are showing. Since the fan is not on constantly, I suppose that means when the fan is not on it uses almost nothing. So one question is how long does the fan actually run over one 24 hour period, which would then be the actual amps used during that period.

If the above actually makes sense, don't be fooled into thinking I actually know what I am talking about.

In my 21RB., when only the main battery disconnect switch turned to on, and everything else with a switch (tv, fridge, all lights, water heater, water pump, furnace, etc) is off, the Victron Connect reports .2 Amps. When I first turn the furnace on, the Victron reports around 7.4 Amps so the furnace is using about 7.2 Amps. When the burner comes on the Victron reports an increase to about 7.9-8.2 Amps. So it seems like it's using slightly more current, perhaps the furnace has some additional monitoring circuitry when the burner is on. When I turn the thermostat down, or off, the blower stays on for a few minutes, which I assume is to make sure no propane remains in the chamber. Again the Victron reports 7.4 Amps.



The Bigfoot specs page reports the 21' and 25' models all have a 30,000 BTU furnace. I am guessing it's the same model but can't say for sure. As Gordon2 wrote, how long the fan runs in a 24 hour period is going to depend on many factors. So I can't really say. Your Bigfoot is 4 feet longer than mine, so roughly 20% more area which will take longer to heat. Also, it depends on how warm you want it, and how cold is it outside, etc.


The only time I spent a night in the Bigfoot when it was actually cold enough to really need the furnace, it stopped working. It was 34 outside and 43 inside when I woke up, and I was pretty cold. It's working again but I haven't camped out in it since it was repaired.



Hope this helps.
JonRaw is offline   Reply With Quote
Old 01-19-2020, 03:51 AM   #22
Senior Member
 
Name: Henry
Trailer: BigFoot
Tennessee
Posts: 1,312
Thanks everyone. I take the trailer in Monday to the RV Service center to determine what is needed. I like k corbins idea of working backwards and will approach it this way.
Rzrbrn is offline   Reply With Quote
Old 01-19-2020, 08:01 AM   #23
Senior Member
 
Name: Gordon
Trailer: 2015 Scamp (16 Std Layout 4) with '15 Toyota Sienna LE Tug
North Carolina
Posts: 5,156
Quote:
Originally Posted by Rzrbrn View Post
Thanks everyone. I take the trailer in Monday to the RV Service center to determine what is needed..
Or how much profit they need.
gordon2 is offline   Reply With Quote
Old 01-19-2020, 11:23 AM   #24
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
I tried to go the same path as you, and ran into some of the same difficulties and advice that "you won't know till you do it". On some level, the answer is to start conservative, building a system that is easy to add on to, rather than thinking you can know how much power you use and match a system perfectly.

I used what I thought would be my highest draw on all appliances, based on early spring/late fall. 20s at night, 30s or 40s during the day. My Bigfoot is smaller, but I got just under 340amp/hours per week. And the Go Power calculator wanted me to buy at least 200w of solar. I have more power than I need with 100w, in practice.

I'd encourage you to do the calculations yourself. I more than cut in half some of the figures Go Power came up with when I looked at my actual appliances and their stated draw, rather than the general estimated draw from Go Power for that appliance.

If you plan to run AC appliances that's going to be a huge power draw. Are you trying to run a coffee maker, TV? It adds up fast. They're power hogs.

To run your trailer like a house in the winter is going to absolutely require a massive solar array and a battery bank to match. For a 25' trailer, being comfortable, I'd be more inclined to put up 400w of solar, a couple 6v batteries, and modify your electric use to fit that system. Or something similar and reasonable. Keep in mind you're living in a trailer and live accordingly. You know what level of comfort you're willing to endure, so this is just my opinion.

I have a thick down comforter, and my heater does not run at night unless the temps inside the trailer are going to get below 35. Once it drops into the mid-30s I'm not terribly uncomfortable, but I wake up in the fetal position. I live in the north, though. I remember a podcast about getting the best sleep, and the guy was saying that it took getting used to, but he finally gave in to the recommendation that people sleep best if it's 65 degrees at night. That seemed terribly cold to him! But he lives in Austin TX, and I see you're in TN. It's all what you're used to. At 65 I'm sweating in bed.
ZachO is offline   Reply With Quote
Old 01-19-2020, 11:37 AM   #25
Senior Member
 
Name: Henry
Trailer: BigFoot
Tennessee
Posts: 1,312
Thank you Zach, you are spot on. We camp fall/winter, with lowest temps in upper teens to hot desert, 110º or so. I suppose I really only need enough electric to be able to run the furnace all night at 50º (maybe even 40º), the refrigerator all day, with enough left over electric to start the propane generator in the morning.

The rest is superfluous unless it can be done...That is, would like to have but not absolutely needed:

TV, which is a DC Jensen, not AC
Blu Ray player is AC
Coffee Maker is AC
Instant Pot is AC
Lights are LED DC
Cell Phone chargers are AC
Microwave is AC
Fantastic Fan may be DC (don't remember)
Computer, Laptop, at least one but 2 is best.
Rzrbrn is offline   Reply With Quote
Old 01-19-2020, 11:48 AM   #26
Senior Member
 
ZachO's Avatar
 
Name: Z
Trailer: Sasquatch
Montana
Posts: 2,561
I think the Go Power calculator is good for usage, but don't take their recommendations for a system.

For example, their inverter recommendations come from what you need to run all AC appliances at the same time. A safe recommendation, but not a realistic one. With my calculations, they also recommended enough battery storage to get me through 5 days with no recharge. Their recommendation essentially assumes no solar, which is weird...

I used their calculator to familiarize myself with the process, then did all the calculations myself, looking at each individual appliance, electronic device and charger I own. My calculations where much lower. I run very, very little through an inverter, though.

Also, you can never know how much charge you'll get on a given day, so it always comes down to some guess work.

Jon's system for his 21' trailer is probably a great starting place for you. The Bigfoot is bigger in a lot of ways, but in the same ballpark. Somewhere in the 400w solar array and 200 or more amp hours of battery storage is a reasonable place to start. Especially since you've got a generator to fall back on while you figure it out.

My calculations included a 16,000btu furnace (6 hrs/day), LED lights, cell phone charger, one laptop charger, an occasional charging of some power tools, and two 12v fans, along with 1 hour/day of the water pump running. You should at least be easily able to check a few of those "not absolutely needed" appliance boxes.

What gets you, though, is "household" style usage. When I entered the number of hours my laptop needs to charge if I'm working a 6-8 hour day at home, holy cow! Lots of energy. If you're planning to truly live off grid for a winter, well, I guess you need a big system. But unless you want a giant system, you may need to give in and realize you can't have quite all the comforts of home. Do what you can to charge the laptop while driving, and when you're in a library or laundromat, and keep your use down. There are dozens of ways like that to reduce battery draw. Play around on Go Power with how cutting down the hours of use especially for AC appliances drastically cuts your amp hours. Whether you want to live that way, or have things just how you want them and are used to them at home is up to you!
ZachO is offline   Reply With Quote
Old 01-19-2020, 05:58 PM   #27
Commercial Member
 
Name: Mel
Trailer: aliner
Texas
Posts: 46
A low cost way to know the power you're using is to monitor the 120vac your camper uses while plugged in for a night. You can do this easily do this by:

1. Select and purchase one of the a $25-$35 Kill-A-Watt meters. Altex, Home Depot, Amazon usually have them.
2. Ensure you have the adaptors to use the Kill-A-Watt to monitor your incoming power.
3. Try at home if possible before traveling to ensure you know how to use it (very simple)

Go camping and:
1. Check into a powered park for one night (shower night perhaps?).
2. Unplug or turn your fridge to run on LP for the night as if you're camping.
3. Plug in the Kill-A-Watt.
4. The next day, record the use (Wh) and time (Hours)
5. Multiply to get your 24hour use average.

After you get that, I'd appreciate your contacting me directly. Depending on your use, I can tell you my recommendations. Some are very inexpensive.
I too have a small camper in which we spend most of our camping off-grid. Our 10 week trip to Alaska, mostly off-grid, proved to me my solar and LFP battery system supplies all I need. MelH
MelH is offline   Reply With Quote
Old 01-19-2020, 07:07 PM   #28
Senior Member
 
Name: Gordon
Trailer: 2015 Scamp (16 Std Layout 4) with '15 Toyota Sienna LE Tug
North Carolina
Posts: 5,156
Quote:
Originally Posted by MelH View Post
...

1. Select and purchase one of the a $25-$35 Kill-A-Watt meters....
Welcome to the forum Mel.

Using a Kill-A-Watt is a good idea.

However a few points.

First, it is rated to 15 amps (about 1800 watts) so be sure to not exceed that. In fact staying under 1500 watts is a good idea.

Second, When using the Kill-A-Watt with shore power to estimate off grid power use be sure to avoid the temptation to use anything on 120 volts other than the converter. No A/C, no microwave... nothing plugged into an outlet. Using the fridge (on propane of course) is recommended since it might have a control board that uses a little 12 VDC power.

Third, start with a fully charged battery, or better yet disconnect the battery (as long as your converter works with no battery – most do.) If the battery starts off partially discharged, then your data will reflect both power used in the camper AND power used to recharge the battery.

Fourth, understand that there is some power use overhead when only using the converter since it is not 100% efficient. But this will actually give you a little over estimation of your actual power usage and that is a good thing… to have a little margin over actual usage. And it will be somewhat balanced by the fact that battery recharging is not 100% efficient. So basically, you can ignore point number 4 .

Fifth, a single 24 hours will only tell you roughly how much power you used in THAT 24 hours. Differing conditions, weather, etc. will yield different results. So a full time battery monitor is still a good idea for the long term.

But for a base line, properly using the Kill-A-Watt is a good idea. I have one and use it around the house also. Its a handy item.
gordon2 is offline   Reply With Quote
Old 01-20-2020, 09:49 AM   #29
Senior Member
 
Perryb67's Avatar
 
Name: Perry
Trailer: 2016 Bigfoot 25RQ
Lanesboro, Minnesota, between Whalan and Fountain
Posts: 768
FYI:
The Victron 712 Smart Battery Monitor does have the screen Jon shows in post 10. However, the screen Jon shows in post 12 is not available with the Victron 712. I was disappointed after contacting Victron to find you only get long term history with the Smart Controller.

I do find the 712 very useful, but wouldn't have wasted my money on the monitor had I known the history chart that Jon shows was not available with the 712. I would have purchased a Smart Controller to have the information that Jon shows.

Edit: I just completed the GoPower Solar Calculator set for Fall-Winter. It estimated we use 49 amp hours a day with the furnace running 2 hours a night (set to 55 degrees). I feel this is on the high side, but the Victron 712 does not give me any reading to really know what we use in a day, just where we currently are vs 100% full.

To save battery power we use a portable Mr Buddy to quickly heat up our camper when we go inside for the night, and in the morning to quickly heat the camper up to dress and for coffee and breakfast when really cold outside.

If our batteries get low, we have a Martin catalytic heater that puts out 1,500 BTU's to use, instead of the furnace, till we get enough sun to charge our batteries. Yes, we know to crack a window for venting and have two CO detectors.

We have a single 170 watt GoPower panel and a GoPower controller for our Escape 5.0.

Enjoy,

Perry
__________________
2016 Bigfoot 25RQ - 2019 Ford F-150, 3.5 V6 Ecoboost,

Previous Eggs -2018 Escape 5.0 TA, 2001 Scamp 16' Side Bath, 2007 Casita 17' Spirit basic, no bath, water or tanks, 2003 Bigfoot 25B25RQ, that we regreted selling
Perryb67 is offline   Reply With Quote
Old 01-20-2020, 11:30 AM   #30
Senior Member
 
Jon Vermilye's Avatar
 
Name: Jon
Trailer: Escape 21C
New York
Posts: 2,396
Registry
Quote:
Originally Posted by Perryb67 View Post
FYI:
The Victron 712 Smart Battery Monitor does have the screen Jon shows in post 10. However, the screen Jon shows in post 12 is not available with the Victron 712. I was disappointed after contacting Victron to find you only get long term history with the Smart Controller.

I do find the 712 very useful, but wouldn't have wasted my money on the monitor had I known that history chart that Jon shows was not available with the 712 with the furnace running. I would have purchased a Smart Controller to have the information that Jon shows.

Edit: I just completed the GoPower Solar Calculator set for Fall-Winter. It estimated we use 49 amp hours a day with the furnace running 2 hours a night (set to 55 degrees). I feel this is on the high side, but the Victron 712 does not give me any reading to really know what we use in a day, just where we currently are vs 100% full.

We use a portable Mr Buddy to quickly heat up our camper when we go inside for the night, and in the morning to quickly heat the camper up to dress and for coffee and breakfast when really cold outside.

If our batteries get low, we have a Martin catalytic heater that puts out 1,500 BTU's to use instead of the furnace till we get enough sun to charge our batteries. Yes, we know to crack a window for venting and have two CO detectors.

We have a single 170 watt GoPower panel and a GoPower controller for our Escape 5.0.

Enjoy,

Perry
Yes, this screen is from the Victron 100/30 Solar Controller, not the 712 Smart. While there is a history page on the 721 Smart, I haven't found it all that useful, other than being able to see the lowest lifetime discharge, and the last discharge.
Jon Vermilye is offline   Reply With Quote
Old 01-21-2020, 05:22 PM   #31
Commercial Member
 
Name: Mel
Trailer: aliner
Texas
Posts: 46
Quote:
Originally Posted by gordon2 View Post
Welcome to the forum Mel.

Using a Kill-A-Watt is a good idea.

However a few points.

First, it is rated to 15 amps (about 1800 watts) so be sure to not exceed that. In fact staying under 1500 watts is a good idea.

Second, When using the Kill-A-Watt with shore power to estimate off grid power use be sure to avoid the temptation to use anything on 120 volts other than the converter. No A/C, no microwave... nothing plugged into an outlet. Using the fridge (on propane of course) is recommended since it might have a control board that uses a little 12 VDC power.

Third, start with a fully charged battery, or better yet disconnect the battery (as long as your converter works with no battery – most do.) If the battery starts off partially discharged, then your data will reflect both power used in the camper AND power used to recharge the battery.

Fourth, understand that there is some power use overhead when only using the converter since it is not 100% efficient. But this will actually give you a little over estimation of your actual power usage and that is a good thing… to have a little margin over actual usage. And it will be somewhat balanced by the fact that battery recharging is not 100% efficient. So basically, you can ignore point number 4 .

Fifth, a single 24 hours will only tell you roughly how much power you used in THAT 24 hours. Differing conditions, weather, etc. will yield different results. So a full time battery monitor is still a good idea for the long term.

But for a base line, properly using the Kill-A-Watt is a good idea. I have one and use it around the house also. Its a handy item.
Thanks for the good add-ons to my advice!
I haven't worked with off-grid campers that used more than 1500W; glad you mentioned it.
I also should have mentioned to operate as if you're off-grid; no 120vac electric heaters, hair dryers, coffee pots, etc. Thanks for catching my oversight.

Sorry for the delayed response. I just finished building another copy of my charge system for my smart LFP battery. It's cool! Will install next month for a friend.
The smart 125ah LFP battery provides all info via bluetooth (SoC, V, A, temp, protection status', etc.)to owner phone along with auto-calibration and balancing when charged to 100% each 1-2 weeks.
The MPPT solar controller monitors load power, stores up to 30 days data, and provides all info to phone via Bluetooth.
The converter/charger has algorithms to prevent overcharge the battery.
By taking care of charge strategies, I hope to get the 8000 discharge cycles it's tested to provide.
BTW, we 'camp' in comfort. Daily, we use about 230Wh and generate about 520Wh w/100W suitcase solar. Life is good!
MelH
MelH is offline   Reply With Quote
Old 01-22-2020, 02:49 AM   #32
Senior Member
 
Name: Henry
Trailer: BigFoot
Tennessee
Posts: 1,312
I Just talked to the RV SERvice center that I expect to be doing my solar install. Keep in mind that I do not know anything about electricity. I have a 2019 Big Foot 25RQ solar ready (don't know exactly what this means). Please excuse the upper case, I am lazy and am just copy and pasting. I just had a phone conversation to get the overall proposal, and will meet with the RV Service tech to get a written estimate within the next couple of days.

OK, this is what is being proposed:

Renogy 600 WATT 24 VOLT SOLAR PREMIUM KIT (4 panels in front + 2 panels in the rear, all on top permanently mounted on tracks bolted to the roof).

This kit includes:

6 ECLIPSE - 100 WATT 12 VOLT MONOCRYSTALLINE SOLAR PANELS

ROVER LI 40 AMP MPPT SOLAR CHARGE CONTROLLER with Blue tooth module, paired to the Renogy BT APP. The Renogy BT APP allows remote monitoring. This kit also consists of six sets of mounting Z-Brackets, branch connectors, one 20ft 10AWG MC4 Adaptor Kit, one 8ft 8AWG Tray Cable, and fusing components for protection of the controller and battery.

Not in kit but being added:

MAGNUM INVERTER. Not certain which one at this point, will know and update after I visit the RV Service technician.

USB ports will be wired with on/off switches

Two 100Ah 12V LiFePO4 Deep Cycle Batteries, expandable to two more if desired at a later date.

What do you think?

Not certain what else is to be include, will update later.
Rzrbrn is offline   Reply With Quote
Old 01-22-2020, 04:28 AM   #33
Senior Member
 
Name: Jon
Trailer: Bigfoot
California
Posts: 193
Quote:
Originally Posted by Rzrbrn View Post
I Just talked to the RV SERvice center that I expect to be doing my solar install. Keep in mind that I do not know anything about electricity. I have a 2019 Big Foot 25RQ solar ready (don't know exactly what this means). Please excuse the upper case, I am lazy and am just copy and pasting. I just had a phone conversation to get the overall proposal, and will meet with the RV Service tech to get a written estimate within the next couple of days.

OK, this is what is being proposed:

Renogy 600 WATT 24 VOLT SOLAR PREMIUM KIT (4 panels in front + 2 panels in the rear, all on top permanently mounted on tracks bolted to the roof).

This kit includes:

6 ECLIPSE - 100 WATT 12 VOLT MONOCRYSTALLINE SOLAR PANELS

ROVER LI 40 AMP MPPT SOLAR CHARGE CONTROLLER with Blue tooth module, paired to the Renogy BT APP. The Renogy BT APP allows remote monitoring. This kit also consists of six sets of mounting Z-Brackets, branch connectors, one 20ft 10AWG MC4 Adaptor Kit, one 8ft 8AWG Tray Cable, and fusing components for protection of the controller and battery.

Not in kit but being added:

MAGNUM INVERTER. Not certain which one at this point, will know and update after I visit the RV Service technician.

USB ports will be wired with on/off switches

Two 100Ah 12V LiFePO4 Deep Cycle Batteries, expandable to two more if desired at a later date.

What do you think?

Not certain what else is to be include, will update later.

Bigfoot solar ready means that there are heavy duty (maybe 2 or 4 AWG, not sure) wires run from the roof to the underside of the Bigfoot at the factory. The roof side are most likely under the cover to the fridge vent. They go to through the fridge vent to the inside of the trailer (mine are under the counter near the stereo but I have a 21RB.) The wires are cut there to accomodate the solar controller. They then continue back out through the floor of the trailer and the final termination point is under the Bigfoot somewhere near the battery. In the first picture you can see the 2 red and 2 black wires taped together. That is behind my stereo. The second picture was taken looking up at the bottom of the exterior of the Bigfoot.

In my opinion USB ports don't really need switches. Unless something is plugged in, I think the power draw is almost nothing. I suppose it won't hurt, but seems like a pain to remember to turn the switches on or off.

Also my opinion but I don't know what the 8AWG and 10 AWG wires you mention are for. 10 AWG is not enough to run from the battery to the controller, and 8 and 10 AWG are way way too small for the inverter to battery cables.
Attached Thumbnails
20190729_184220.jpg   20190729_184734.jpg  

JonRaw is offline   Reply With Quote
Old 01-22-2020, 06:22 AM   #34
Senior Member
 
OCJohn's Avatar
 
Name: John
Trailer: Hymer
California
Posts: 200
Registry
24v allows them to drop the wire size, no?
OCJohn is offline   Reply With Quote
Old 01-22-2020, 10:00 AM   #35
Senior Member
 
Perryb67's Avatar
 
Name: Perry
Trailer: 2016 Bigfoot 25RQ
Lanesboro, Minnesota, between Whalan and Fountain
Posts: 768
Quote:
Originally Posted by Rzrbrn View Post

OK, this is what is being proposed:

Renogy 600 WATT 24 VOLT SOLAR PREMIUM KIT (4 panels in front + 2 panels in the rear, all on top permanently mounted on tracks bolted to the roof).
We've owned a 25 RQ.

Question I'd ask the installer, "How will the tracks be bolted to the roof?"

Will you have unsightly plates in your living area?

Personally, I'd be glueing legs rather than bolting.

Enjoy,

Perry
Perryb67 is offline   Reply With Quote
Old 01-22-2020, 10:49 AM   #36
Senior Member
 
Name: Henry
Trailer: BigFoot
Tennessee
Posts: 1,312
Perry, the RV tech stated that the glue technology has not been around long enough to know if panels only glued to the roof with remain so 10 or 15 years down the road. With bolts you know it will hold. I don't expect to be around 15 or 20 years from now, but my kids may have the trailer and having the possibility of the panels flying off when on the road is a chance I don't want to take. I don't mind a few bolts in the ceiling, although I can't say that my wife will find it appealing...
Rzrbrn is offline   Reply With Quote
Old 01-22-2020, 11:02 AM   #37
Senior Member
 
Name: Henry
Trailer: BigFoot
Tennessee
Posts: 1,312
Quote:
Originally Posted by JonRaw View Post
Bigfoot solar ready means that there are heavy duty (maybe 2 or 4 AWG, not sure) wires run from the roof to the underside of the Bigfoot at the factory. The roof side are most likely under the cover to the fridge vent. They go to through the fridge vent to the inside of the trailer (mine are under the counter near the stereo but I have a 21RB.) The wires are cut there to accomodate the solar controller. They then continue back out through the floor of the trailer and the final termination point is under the Bigfoot somewhere near the battery. In the first picture you can see the 2 red and 2 black wires taped together. That is behind my stereo. The second picture was taken looking up at the bottom of the exterior of the Bigfoot.

In my opinion USB ports don't really need switches. Unless something is plugged in, I think the power draw is almost nothing. I suppose it won't hurt, but seems like a pain to remember to turn the switches on or off.

Also my opinion but I don't know what the 8AWG and 10 AWG wires you mention are for. 10 AWG is not enough to run from the battery to the controller, and 8 and 10 AWG are way way too small for the inverter to battery cables.
JonR, the 8 and 10 AWG wires are what Renogy has in its literature and instruction for their 24V solar panel kit. With 24V, thicker wires are apparently not needed for long runs. Increasing the voltage of a system causes a reduction in the current through it, and in turn reduces the size of the wires you need .
Rzrbrn is offline   Reply With Quote
Old 01-22-2020, 11:42 AM   #38
Commercial Member
 
Name: Mel
Trailer: aliner
Texas
Posts: 46
This is a fairly big system to me; they've wisely erred on the side of caution and they're assuming you continue using the OEM appliances. System support (local or remote) is also important. I understand the appeal. Ask if the batteries have cell-to-cell equalization (extends battery life) and how their SOC (%charge) recalibration works. These sometimes do not exist or are a pain to do.

I took a slightly different track of reducing electrical energy, using LP when possible, and parking in the shade (lousy solar, but cooler). My biggest benefits have come from:
1. Using a Camco Wave 6 heater instead of the OEM heater. Quiet, no electricity, works at high altitudes, and no CO.
2. Using a 3-way fridge on LP when camping. Interestingly, my two most recent energy upgrades were for people with electric only fridges (30-50W avg.)
3. Parking in the shade and using a folding solar panel and long cord. It also avoids my installing solar panels on roof.
4. Going North and High in summer (no Air Conditioning needed) and South or desert in winter.
5. Checking and monitoring power 1/day (about 1 minute) using BT and phone.
6. Use of my 1000W inverter only when I need it - computer recharge, wife's lathe. Could be used sparingly for other appliances but I'd monitor battery power.

Let me know what power you measure. If interested, I might be able to help you with a system like mine (see pics).
All battery, solar, and load info provided via BT to phone.
Only the small charge control 3-position toggle switch needs easy access.
Only the shown 2 pieces of equipment to install or transfer to another camper (along with wiring).

I look forward to hearing from you! MelH

BTW, the wiring of my system is 6AWG f/battery and inverter, 10AWG for the rest.



Quote:
Originally Posted by Rzrbrn View Post
I Just talked to the RV SERvice center that I expect to be doing my solar install. Keep in mind that I do not know anything about electricity. I have a 2019 Big Foot 25RQ solar ready (don't know exactly what this means). Please excuse the upper case, I am lazy and am just copy and pasting. I just had a phone conversation to get the overall proposal, and will meet with the RV Service tech to get a written estimate within the next couple of days.

OK, this is what is being proposed:

Renogy 600 WATT 24 VOLT SOLAR PREMIUM KIT (4 panels in front + 2 panels in the rear, all on top permanently mounted on tracks bolted to the roof).

This kit includes:

6 ECLIPSE - 100 WATT 12 VOLT MONOCRYSTALLINE SOLAR PANELS

ROVER LI 40 AMP MPPT SOLAR CHARGE CONTROLLER with Blue tooth module, paired to the Renogy BT APP. The Renogy BT APP allows remote monitoring. This kit also consists of six sets of mounting Z-Brackets, branch connectors, one 20ft 10AWG MC4 Adaptor Kit, one 8ft 8AWG Tray Cable, and fusing components for protection of the controller and battery.

Not in kit but being added:

MAGNUM INVERTER. Not certain which one at this point, will know and update after I visit the RV Service technician.

USB ports will be wired with on/off switches

Two 100Ah 12V LiFePO4 Deep Cycle Batteries, expandable to two more if desired at a later date.

What do you think?

Not certain what else is to be include, will update later.
Attached Thumbnails
IMG_2052.jpg   IMG_2053.jpg  

MelH is offline   Reply With Quote
Old 01-22-2020, 12:14 PM   #39
Senior Member
 
Raspy's Avatar
 
Name: John
Trailer: Roamer 1
Smith Valley, Nevada
Posts: 2,904
Quote:
Originally Posted by gordon2 View Post



Fourth, understand that there is some power use overhead when only using the converter since it is not 100% efficient. But this will actually give you a little over estimation of your actual power usage and that is a good thing… to have a little margin over actual usage. And it will be somewhat balanced by the fact that battery recharging is not 100% efficient. So basically, you can ignore point number 4 .
Gordon,
Not sure what you are saying here. The inverters are only about 90% efficient, so there is a 10% loss when using them. Plus, they have standby losses that can add up if left on while not running any appliances. Battery charging also has losses of up to about 20-30%, as I understand it. Those two losses must be accounted for somehow and show up as reduced system capacity. So that extra power must also be accounted for somehow too. With batteries and inverters, you put more in than you get out. Plus, with batteries, the higher the amp draw, the less is available overall. So running a microwave, for example can seem to use more than calculated, because the inverter wastes power, the battery wastes power when recharging, and the batteries have lower overall capacity with a heavy amp draw. These three things together might total to a 50% loss in some cases.

Also, everyone should be cautious in estimating solar performance. A 300 watt system will not produce 300 watts if laid flat on the roof. Tracking systems produce about 250% overall, of what flat systems produce.

We all want to have more power and it seems demand will always rise to meet supply. So even a well designed system will seem weak eventually, as more appliances are added. We all have to live within our solar system's abilities. Just yesterday, I got a new electric bike for instance, and charged it from my inverter. A load I did not account for a few days ago. And a large load too.
__________________
I only exaggerate enough to compensate for being taken with a grain of salt.
Raspy is online now   Reply With Quote
Old 01-22-2020, 12:57 PM   #40
Senior Member
 
Name: Gordon
Trailer: 2015 Scamp (16 Std Layout 4) with '15 Toyota Sienna LE Tug
North Carolina
Posts: 5,156
Quote:
Originally Posted by Raspy View Post
Gordon,
Not sure what you are saying here. The inverters are only about 90% efficient, so there is a 10% loss when using them. Plus, they have standby losses that can add up if left on while not running any appliances. Battery charging also has losses of up to about 20-30%, as I understand it. Those two losses must be accounted for somehow and show up as reduced system capacity. So that extra power must also be accounted for somehow too. With batteries and inverters, you put more in than you get out. ...
We were only talking about using a Kill-a-Watt device to estimate the power draw of the 12 volt stuff alone. Using the Kill-a-Watt on the shore power line would record the power draw of the 12 volt stuff as it is being powered by the converter instead of the house battery. It would therefore be a good estimation of what the draw would have been if the battery were the power source instead, with the slight variation being the efficiency (power overhead) of the converter.

Using an inverter powered by the converter which is powered by shore power was not part of the idea. Nor was recharging the battery since that would depend on length of time each 12 volt item was used, and the battery manufacture's charging recommendation which typical includes about a ten percent "over charge."

The Kill-a-Watt only records the watts (and amp hours, voltage and frequency) on a 120 VAC line and is useless for directly measuring DC current, battery charging, etc. Your solar efficiency, inverter (if you must have one), etc. are beyond the scope of my comment as quoted.
gordon2 is offline   Reply With Quote
Reply

Tags
solar


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Travel Trailer Tow Calculator 1Oldman Towing, Hitching, Axles and Running Gear 4 03-15-2015 08:09 PM
Link to battery sizing calculator Timber Wolf Modifications, Alterations and Updates 0 07-24-2014 07:32 AM
Travel Trailer Calculator steve dunham Towing, Hitching, Axles and Running Gear 29 06-02-2014 08:30 PM
Towing a travel trailer weight calculator cpaharley2008 Towing, Hitching, Axles and Running Gear 0 10-29-2013 04:33 PM
Tilt Angle Calculator for Solar panels Kevin K Problem Solving | Owners Helping Owners 4 06-12-2012 03:36 PM

» Upcoming Events
No events scheduled in
the next 465 days.
» Featured Campgrounds

Reviews provided by


All times are GMT -6. The time now is 07:07 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.